Contemporary air boats are commonly used in shallow water and swamp land such as the Florida Everglades, for example. These boats draw very little water and are air-propelled by an aircraft type propeller. Typically, these boats are powered by an opposed aircraft engine which is mounted high above the hull to provide adequate clearance for the rotating propeller which is normally axially aligned with the engine crankshaft. Because of the high-mounted engine, the center of gravity of the air boat is rather high. Placement of an engine low in the air boat hull substantially lowers the center of gravity and provides a more stable boat. Numerous patents show air boats with low-mounted engines drivingly connected with elevated propellers independently mounted on the hull or superstructure of a large boat or ship. However, contemporary air boats are relatively small and such independent mounting of the engine and propeller may cause considerable stress in the hull and additionally complicates servicing of the equipment. For example, if the engine requires major servicing this is often done on the boat in typical inboard installations. However, working on an engine in a small boat is not only inconvenient, the labor charges are often substantially higher than comparable charges if the engine is removed from the boat. Removal of a typical inboard engine entails considerable work within the boat in order to disconnect fuel lines, cooling system connections, and the drive train. Once the engine has been removed from the boat and serviced and the engine is returned to the boat these connections must again be made and, if other work is to be done on the fuel tank or parts of the cooling system these components must generally be handled separately from the engine.
As previously mentioned, various patents show air boats having relatively low-mounted engines drivingly connected with independently mounted propellers, and these patents include: U.S. Pat. Nos. 970,532; 998,193; 1,048,337; 1,104,428; 1,459,979; 1,641,937; and 2,341,911. However, as shown in these patents, the propeller and engine are mounted on the boat or vehicle independently of each other.